KR20100119554A - Primers and a method of coating in which they are used - Google Patents

Abstract

The present invention is a primer having excellent adhesion to a plastic material, excellent interlayer adhesion with a paint film forming a base when re-coating or repainting, and coating using such a primer It is to provide a method.
[Solution] (A) Chlorinated polyolefin resin having a chlorine content of 5 to 50% by mass and a weight average molecular weight of 1,000 to 100,000, (B) Blocked polyisocyanate compound, (C) A hydroxyl value of 30 to 120 mgKOH / g, and weight A polyol resin having an average molecular weight of 5,000 to 50,000, (D) a diol having a weight average molecular weight of 120 to 1,000, and (E) a curing catalyst, wherein the content ratio of the above components is included (A) component, (B) (A) component is 50-90 mass%, (B) component is 45-5 mass%, (C) component is 45-5 mass% with respect to the total mass of the resin solid content of a component and (C) component, (D A primer which is 0.5-12 mass% of a component, and 0.01-1.5 mass% of (E) component.

Description

Primer and coating method using the same {PRIMERS AND A METHOD OF COATING IN WHICH THEY ARE USED}

The present invention relates to a primer having excellent adhesion on a plastic material, especially a polyolefin material, and excellent adhesion to a surface paint film without sanding when re-coating or repainting, and a coating using the same. It is about a method.

Polyolefin molded articles are commonly used, for example, as members of automobile exterior plates, home appliances, and the like, and recently, recycled polyolefin molded articles are also reused. When using a two-liquid type top-coat paint containing a polyisocyanate compound as a top-coat paint of a polyolefin molded article, in order to improve the adhesion between the top-coat paint film and the polyolefin molded article, Primers containing chlorinated polyolefins have been used. However, when a rubber product contained in a polyolefin molded article (for example, styrene / butadiene rubber, isoprene rubber, etc.) and a recycled polyolefin molded article in which a small amount of hydroxyl group-containing polyolefin is added or not added are reused, There is a problem of insufficient adhesion.

In addition, after coating the primer and the top-coat paint on the polyolefin molded article, when repair-coating is performed, the paint film is usually sanded to remove dust, stains, etc. And re-painted (recoated) with top-coat paint. In this case, it is possible to recoat by primer and top-coat paint on the unpainted paint film (without sanding) without polishing the entire surface of the paint film to be repaired. In such a case, there is a drawback of insufficient interlayer adhesion between the lower layer paint film and the primer to be recoated.

A two-liquid type paint composition having a high gloss appearance, weather resistance, solvent resistance, and coating workability while providing excellent adhesion by coating directly on a hard-adhesive polyolefin material without coating a primer. Chlorinated polyolefin resin having a content of 10 to 50 mass%, (B) acrylic modified chlorinated polyolefin resin, (C) an acrylic resin having a weight average molecular weight of 2,000 to 50,000 and a hydroxyl group value of 10 to 90 mgKOH / g, and And / or polyester resin and (D) isocyanate compound as essential components, and the ratio of isocyanate equivalent and hydroxyl group equivalent is [isocyanate equivalent] / [hydroxyl equivalent] = 0.5 / 1.0 to 1.2 / 1.0, (A) component is 3-20 mass%, (B) component is 5-40 mass% with respect to the gross mass (solid content) of a component, (B) component, and (C) component, and (C) component is 40 To 92 mass% There is known a composition (for example, see Patent Document 1). However, since this uses both a function as a primer and a function as a top-coat paint, adhesion with a molded article of a polyolefin material is not sufficient, and there is a problem of pot-life in a two-liquid type paint. .

In addition, it is possible to form a paint film that can be directly coated on a molded article of a polyolefin-based material without the need for a pretreatment process such as primer coating, and has excellent storage stability and excellent adhesion, hot water resistance, and gasoline resistance. A resin composition for paints, which is (1) polymerizing or copolymerizing an acetoacetoxy group-containing monomer with another monomer copolymerizable as necessary in the presence of 5 to 50 parts by weight of a chlorinated polyolefin resin having a chlorine content of 15 to 50% by weight. A resin composition for paints having good adhesion to a polyolefin-based material is known, comprising a polymer having an acetoacetoxy group and (2) an isocyanate compound in the side chain obtained as an essential component (for example, a patent See Document 2. However, such a resin composition for paints is a two-liquid type paint and has a problem of pot life.

Further, a primer for plastic having excellent adhesion to molded articles of polyolefin-based materials and re-coating adhesion to paint films, wherein (A) chlorination has a chlorine content of 16 to 22% by weight and a weight average molecular weight of 30,000 to 120,000. Polyolefin, (B) isocyanurate type aliphatic and / or cycloaliphatic polyisocyanate containing blocked polyisocyanate and (C) polyol resins blocked by malonic acid dialkyl esters and acetoacetic acid esters The primer for plastics is known (for example, refer patent document 3). However, the adhesion when the molded article or the paint film of the polyolefin-based material is sanded is good, but the re-coating adhesion when not sanded is insufficient.

[Patent Document 1]

Japanese Patent Publication No. 2005-139336

[Patent Document 2]

Japanese Patent Publication No. H8-311397

[Patent Document 3]

Japanese Patent Publication No. 2002-121462

The present invention has a good adhesion to plastic materials, in particular polyolefin materials, and with paint films which form a base in top-coat paints during re-coating (repainting), in particular with urethane resin-based top-coat paint films It is an object to provide a primer having excellent interlayer adhesion, and to provide a coating method using the primer.

The present inventors conducted research to solve the above problems, and as a result, a low molecular weight diol and a curing catalyst were added to a composition containing a specific chlorinated polyolefin resin, a specific hydroxyl group-containing polymer polyol resin, and a blocked polyisocyanate compound. By addition, it has been found that re-coating adhesion to molded articles or paint films comprising plastic materials, such as polyolefin-based materials, is significantly improved, and the present invention has been completed based on this.

That is, in the present invention, (A) a chlorinated polyolefin resin having a chlorine content of 5 to 50 mass% and a weight average molecular weight of 1,000 to 100,000, (B) a blocked polyisocyanate compound, and (C) a hydroxyl group value of 30 To 120 mgKOH / g, a polyol resin having a weight average molecular weight of 5,000 to 50,000, (D) a diol having a weight average molecular weight of 120 to 1,000 and (E) a curing catalyst, the content ratio of the components contained, (A) component is 50-90 mass%, (B) component is 45-5 mass%, and (C) component is the total mass of resin solid content of (A) component, (B) component, and (C) component. It is providing the primer which is 45-5 mass%, (D) component is 0.5-12 mass%, and (E) component is 0.01-1.5 mass%.

In another aspect, the present invention is to provide a coating method of a plastic molded article, characterized in that the coating and baking and curing of the primer and the top-coat paint sequentially on the plastic molded article to form a top-coat paint film.

In addition, the present invention, after sequentially coating, baking and curing the primer and the top-coat paint on a plastic molded article, and sequentially coating the primer and the top-coat paint on the top-coat paint film To provide a coating method of a plastic molded article characterized by baking, curing.

Further, the present invention sequentially coats the primer and the top-coat paint on the molded article on which the top-coat paint is coated, cured and the top-coat paint film is formed, baked and cured. It is to provide a method for coating a molded article characterized in that.

The present invention also provides a coating method of the molded article, wherein the top-coat paint is a one-coat type two-liquid type urethane resin paint. It is to provide a coating method.

In addition, the present invention provides a coating method of the molded article, wherein the top-coat paint film comprises two layers of a base coat paint film and a clear paint film, at least 2 clear paints It is to provide a coating method of a molded article which is a liquid type urethane resin paint.

The present invention also provides a coating method of the molded article, wherein the top-coat paint film is composed of three layers of a colored basecoat paint film, a pearl basecoat paint film, and a clear paint film, and at least the clear paint is a two-liquid. It is providing the coating method of the molded article which is a type urethane resin paint.

By using the primer according to the present invention, the urethane resin-based top-coat paint film and the primer which are excellent in adhesion of the primer paint film on a plastic material, especially a polyolefin material, and also form a base in re-coating (re-painting) A paint film excellent in the interlayer adhesion of the paint film can be obtained.

Chlorinated polyolefin resin which is (A) component used in this invention has a chlorine content of 5-50 mass%, Preferably it is 15-35 mass%, Most preferably, it is 18-25 mass%. When the chlorine content exceeds 50% by mass, the adhesion to plastic materials, in particular polyolefin material or paint film, is poor, and when the chlorine content is less than 5% by mass, the solubility in the solvent is lowered. This happens.

In addition, the weight average molecular weight of the chlorinated polyolefin resin which is (A) component is 1,000-100,000, Preferably it is 5,000-90,000, Most preferably, it is 10,000-80,000. When the weight average molecular weight exceeds 100,000, there arises a problem of poor coating workability, and when the weight average molecular weight is less than 1,000, there is a problem that a normal paint film cannot be obtained because the cohesive force of the resin itself is insufficient.

As a chlorinated polyolefin resin which is (A) component, the resin in which the polymer resin which makes polyolefin resin the main skeleton is modified by chlorine is mentioned. As the polyolefin resin, not only polyethylene resin, polypropylene resin and the like, but also modified polyolefin resin modified with maleic anhydride or the like, or a hydroxyl group, a carboxyl group, a methacryloyl group, an acryloyl group or an epoxy group The polyolefin type high molecular compound which has a molecular terminal or in a molecular ring can be mentioned.

Specific examples of the chlorinated polyolefin resin as the component (A) include chlorinated polyethylene resins, chlorinated polypropylene resins, chlorinated ethylene-propylene copolymers, chlorinated ethylene-vinyl acetate copolymers, and acid anhydrides such as maleic anhydride in such chlorinated polyolefin resins. When copolymerized, modified resin etc. are mentioned.

Moreover, as a chlorinated polyolefin resin which is (A) component, you may use commercially available products. Examples of such products include Superclon 773H, Superclone 822, Superclone 892L, Superclone 832L, Superclone E (manufactured by Nippon Seishi Chemical Co.), Hardren 14LLB, Hard Lene CY9122, hardene HM-21, hardene 13-MLJ (manufactured by Toyo Kasei Kogyo Co.), and the like.

The blocked polyisocyanate compound of the component (B) used in the present invention is one in which a isocyanate group of a polyisocyanate compound having two or more isocyanate groups in one molecule is blocked with a blocking agent. When the blocking agent is removed, the blocked polyisocyanate compound can be expected to react with the polyol resin which is the (C) component. In addition, this ensures the compatibility of the chlorinated polyolefin resin as the component (A) and the polyol resin as the component (C), and serves to enhance affinity with the top-coat paint film.

As the polyisocyanate compound, various polyisocyanates can be used without particular limitation, as long as they have been conventionally used for paint applications. As such polyisocyanate, various polyisocyanates, such as aromatic polyisocyanate, aliphatic or alicyclic polyisocyanate, can be used, for example. Examples of such polyisocyanates include toluene diisocyanate (TDI), or 4, 4-diphenylmethane diisocyanate (MDI), xylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI) ), 2-isocyanate ethyl-2, 6-diisocyanatecaproate (LTI), isophoronediisocyanate (IPDI), trimethyl hexamethylene diisocyanate (TMDI), hydrogenated xylene diisocyanate (HXDI), and the like are suitable examples. Can be. Polyisocyanates can also be used as prepolymers, such as, for example, biuret type, adduct type, or isocyanurate type. From the viewpoint of weather resistance, it is preferable to use aliphatic polyisocyanate. Polyisocyanate may be used individually by 1 type, or may use the polyisocyanate mixture of several types.

Examples of the blocking agent for the polyisocyanate compound are appropriately selected depending on the dissociation temperature, and examples thereof include oxime, active methylene compound, malonic acid dialkyl ester, aceto acetic acid ester, ε-caprolactam, and β-diketone. The blocked polyisocyanate compound may be used alone or in a mixture of several blocked polyisocyanate compounds.

The polyol resin, which is the component (C) used in the present invention, improves the adhesion of the primer paint film to the top-coat paint film, and especially when the curing agent is used in the top-coat paint, the top-coat paint is a urethane resin paint. In the case of, by the reaction with the polyisocyanate derived from the urethane resin paint, serves to improve the cohesion.

The polyol resin as the component (C) has a hydroxyl value of 30 to 120 mgKOH / g, preferably 40 to 70 mgKOH / g, a weight average molecular weight of 5,000 to 50,000, and preferably 7,000 to 20,000. When the hydroxyl value of the polyol resin is less than 30 mgKOH / g, the adhesion decreases due to inadequate crosslink density of the resulting paint film, and when the hydroxyl value exceeds 120 mgKOH / g, it is compatible with chlorinated polyolefin resin (A). Due to the decrease in properties, the storage stability of the primer is lowered, which is not preferable. In addition, when the weight average molecular weight of the polyol resin as the component (C) is less than 5,000, sufficient crosslinked paint film cannot be obtained, adhesion becomes insufficient, and when the weight average molecular weight exceeds 50,000, it is compatible with chlorinated polyolefin resin. The workability at the time of coating falls with property deterioration. Moreover, it is preferable that acid value of the polyol resin which is (C) component is 0-25 mgKOH / g, More preferably, it is 0-10 mgKOH / g. When the acid value of the polyol resin which is (C) component exceeds 25 mgKOH / g, since the storage stability of the paint accompanying the fall of compatibility with chlorinated polyolefin resin falls, it is unpreferable.

As a polyol resin which is (C) component, various polyol resins with the said characteristic can be used, An acrylic polyol resin, a polyester polyol resin, etc. are mentioned as an example. Acrylic polyol resin is obtained by polymerizing or copolymerizing a (meth) acrylic acid ester and / or the copolymerizable polymerizable unsaturated monomer other than the above based on the polymerizable unsaturated monomer containing a hydroxyl group as needed.

As a polymerizable unsaturated monomer containing a hydroxyl group, hydroxy ethyl (meth) acrylate, hydroxy propyl (meth) acrylate, hydroxy butyl (meth) acrylate, 1, 4- butanediol mono- (meth) acrylate, etc. For example. The alkyl alcohol residue having 1 to 18 carbon atoms forming the (meth) acrylate may be any alcohol residue having a straight chain, branched chain, or cyclic alkyl group. These can be used individually by 1 type or in combination of 2 or more types.

Specific examples of the copolymerizable (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, -n-propyl (meth) acrylate, isopropyl (meth) acrylate, -n-butyl (meth) acrylate, Isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate (Meth) acrylic acid alkyl esters such as yarn; (Meth) acrylic acid cyclic hydrocarbon esters such as adamantyl methacrylate and isobornyl (meth) acrylate; (Meth) acrylic-acid aromatic hydrocarbon esters, such as phenyl (meth) acrylic acid, etc. are mentioned. These can be used individually by 1 type or in combination of 2 or more types.

Examples of other copolymerizable polymerizable unsaturated monomers include Hosmer (trade name, manufactured by Unichemical Co.), glycidyl (meth) acrylate, allyl (meth) acrylate, 3, and 4-epoxycyclo. Epoxy group-containing (meth) acrylates such as hexylmethyl methacrylate, allyl methacrylate 3, and 4-epoxycyclohexylmethyl methacrylate; Polymerizable double bond-containing aromatic compounds such as styrene, α-methyl styrene, and p-vinyl toluene; Acrylamide compounds such as methacrylamide, acrylamide, N, N-dimethyl methacrylamide, N, N-dimethyl acrylamide, acrylic acid-2, 2, 6, 6-tetra methyl-4-piperidyl; And aliphatic vinyl ether compounds such as ethyl vinyl ether, isopropyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether and cyclohexyl vinyl ether.

In addition, 2, 3-dihydrofuran; Trimethoxy silyl propyl (meth) acrylate; Maleic anhydride esters, itaconic anhydride esters, maleic acid esters, and fumaric acid esters; Acrylonitrile; Allyl group-containing compounds such as arylglycidyl ether; crotonic acid alkyl esters such as methyl crotonate, ethyl crotonate, and propyl crotonate; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pibarate, vinyl caproate, and capuryl acid Aliphatic carboxylic acid vinyl esters such as vinyl, vinyl caprate, vinyl laurate and vinyl stearate; Alicyclic carboxylic acid vinyl esters such as cyclohexane vinyl carbonate; And aromatic carboxylic acid vinyl esters such as vinyl benzoate, vinyl cinnamic acid, and p-t-butyl vinyl benzoate.

In addition, methacrylic acid, acrylic acid, itaconic acid, mesaconic acid, maleic acid, fumaric acid, ω-carboxy-polycaprolactone (n = 2) mono acrylate [for example, Aronix M-5300 (trade name) , Toa synthesis chemical industry (Toa Gosei Kagaku Kogyo Co. make), phthalic acid monohydroxy ethyl acrylate (for example, Aronix M-5400 (brand name, Toa Synthetic Chemical Co., Ltd. product)), Acrylic acid dimer (for example, Aronix M-5600 (brand name, Toa Synthetic Chemical Industry Co., Ltd. product) etc.) These etc. can be mentioned These can be used individually by 1 type or in combination of 2 or more.

The copolymerizable (meth) acrylic acid ester and the other copolymerizable unsaturated monomers other than the above are not essential components, and in designing the paint film, they are appropriately selected and used according to the requirements of the base material and the purpose of use. Can be.

There is no restriction | limiting in particular about the method of superposing | polymerizing or copolymerizing a polymerizable unsaturated monomer etc. which have a hydroxyl group, For example, well-known methods, such as solution polymerization, suspension polymerization, emulsion polymerization, block polymerization, and precipitation polymerization, can be used in an organic solvent. Can be. Moreover, there is no restriction | limiting in particular also about the said polymerization system, For example, all radical polymerization, cationic polymerization, and anionic polymerization can be used.

Among these methods, radical polymerization is suitable from an industrial point of view. Examples of the polymerization initiator used in the radical polymerization include t-butylhydroperoxide, cumene hydroperoxide, t-butylperoxy neodecanoate, t-butylperoxy pivaloate, t-hexyl peroxy-2 Organic peroxides such as -ethylhexanoate, methyl ethyl ketone peroxide, or 2,2'-azobis (2,4-dimethylvaleronitoryl), 2,2'-azobis (2-methylpropionitoryl Azo initiators, such as (AIBN) and 2, 2'- azobis (2-methyl butyronitrile), are mentioned as a preferable example. Of course, it is not limited to these. These radical polymerization initiators can be used individually by 1 type or in combination of 2 or more types.

As for the reaction temperature at the time of radical polymerization, 60-150 degreeC is preferable normally. When the temperature is less than 60 ° C, the reaction is difficult to proceed because the radical polymerization initiator is difficult to decompose. When the reaction temperature exceeds 150 ° C, even if the radical polymerization initiator decomposes by heat to generate radicals, the life is very long. Since it is short, a growth reaction does not advance effectively. The polymerization time depends on the polymerization temperature and the conditions other than the above, and cannot be generalized and fixed, but generally, a time of about 2 to 6 hours is sufficient.

Moreover, the polyester polyol resin of (C) component can be obtained by making a polybasic acid and polyhydric alcohol react. Examples of the polybasic acid include phthalic anhydride, tetrahydro phthalic anhydride, isophthalic acid, maleic anhydride, fumaric acid, trimellitic anhydride, methylene tricyclohexene tricarboxylic anhydride, pyromellitic anhydride, itaconic acid, adipic acid, seba Succinic acid, azeline acid, hexahydro phthalic anhydride, hymic acid anhydride, succinic anhydride, heptane anhydride and the like. These polybasic acids can be used individually by 1 type or in combination of 2 or more types. Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentylglycol, butylene glycol, hexanediol, trimethol ethane, trimerol propane, pentaerythritol, dipentaerythritol, Sorbitol and the like, and lactone adducts such as caprolactone. These polyhydric alcohols may be used alone or in combination of two or more.

In addition, the polyester polyol resin may be modified by mono-basic acid, fatty acid, oil component and the like. In addition, the hydroxyl group of the polyester polyol resin can be easily introduced by, for example, a polyhydric alcohol having three or more hydroxyl groups in one molecule. The polyol resin which is (C) component can be used individually by 1 type, or can be used in combination of 2 or more type.

In this invention, the ratio of (A) component, (B) component, and (C) component is the total mass of resin solid content of (A) component, (B) component, and (C) component contained, ( A) component is 50-90 mass%, (B) component is 45-5 mass%, and (C) component is 45-5 mass%. Preferably, (A) component is 60-80 mass%, (B) component is 30-10 mass%, and (C) component is 30-10 mass%. Here, the content ratio of each of the above-mentioned (A) component, (B) component, and (C) component is the content ratio of the resin solid content of (A) component, (B) component, and (C) component contained. Means. In addition, resin solid content is a residual part at the time of heating measured using the method of JISK5601-1-2.

When (A) component is less than 50 mass%, the adhesiveness of the primer paint film to a plastic material falls, and when (A) component exceeds 90 mass%, a top-coat paint film and a primer paint film The adhesiveness to and falls. When (B) component is less than 5 mass%, the adhesiveness of a top-coat paint film and a primer paint film falls, and when (B) component exceeds 50 mass%, the primer paint with respect to a plastic material The adhesiveness of a film falls. When (C) component is less than 5 mass%, the adhesiveness of a top-coat paint film and a primer paint film falls, and when (C) component exceeds 50 mass%, the primer paint with respect to a plastic material The adhesiveness of a film falls.

The diol (D) component used in the present invention is a top-coat paint film, especially a urethane resin-based top-coat, which improves the property of chlorinated polyolefin resins to wet the plastic material and forms a base upon re-coating. It serves to enhance the property and adhesion to infiltrate the paint film. In particular, in the lower urethane resin-based top-coat paint film in contact with the primer, when an unreacted isocyanate compound remains near the interface with the primer, the diol having a lower molecular weight than the polyol which is the component (C) is movable ( Because of its high mobility, it is likely to move near the interface in the primer paint film, react with unreacted isocyanate compounds, and improve the interlayer adhesion between the primer paint film and the top-coat paint film during re-coating. Is considered remarkable.

The weight average molecular weight of the diol which is (D) component is 120-1,000, Preferably it is 120-800. When the weight average molecular weight of diol which is (D) component is less than 120, since the solubility in a main aromatic solvent falls, the storage stability of a primer will become low and it is unpreferable. When the weight average molecular weight exceeds 1,000, there is no effect of improving the adhesion to the lower layer top-coat paint film, especially the urethane resin-based top-coat paint film.

Specifically as a low molecular weight diol which is (D) component, dipropylene glycol, triethylene glycol, hydrogenated bisphenol A, etc. are mentioned, for example. Moreover, as a low molecular weight diol which is (D) component, the reaction product of excess diol and dibasic acid, lactone adducts, such as caprolactone with respect to this diol, etc. can also be used. Examples of diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butanediol, neopentyl glycol, pentanediol, hexanediol, heptanediol, octane diol, butylethylpropanediol, and cyclohexane diol , Cyclohexane dimethanol, phenyl dimethanol and the like. Examples of the dibasic acid include dibasic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimeric acid, subberic acid, azeline acid, sebacic acid, terephthalic acid, isophthalic acid, hexahydro terephthalic acid, maleic acid, and fumaric acid. And acid anhydrides of dibasic acids. Modified by glycidyl compounds containing mono-glycidyl groups such as butyl glycidyl ether, 2-ethylhexyl glycidyl ether, sec-butylphenol glycidyl ether, neodecanoic acid glycidyl ester and the like May be

In this invention, content ratio of (D) component is 0.5-12 mass% with respect to the total mass of resin solid content of contained (A) component, (B) component, and (C) component, Preferably it is 1 To 10% by mass, particularly preferably 1.5 to 8% by mass. When the content ratio of component (D) is less than 0.5% by mass, the adhesion of the primer paint film to the top-coat paint film forming the base, especially the urethane resin-based top-coat paint film is insufficient, and exceeds 12% by mass. In this case, since compatibility with the main chlorinated polyolefin resin forming the component (A) is lowered, the storage stability of the primer is lowered, which is not preferable.

In addition, the content ratio of (D) component is an active ingredient content ratio of (D) component, and an active component here means the component which does not contain a solvent etc. when it is diluted with a solvent.

The curing catalyst of component (E) used in the present invention should be one which promotes the reaction between the reactive component contained in the top-coat paint film forming the base and the diol of component (D), and particularly used in urethane resins. Catalyst is preferred. When the top-coat paint film forming the base is a urethane resin-based paint film, it promotes the reaction of the unreacted isocyanate of the urethane resin-based top-coat paint film forming the base with the hydroxyl groups of the re-coated primer layer and does not sand. Improves adhesion when re-coating

As a curing catalyst which is (E) component, a tin compound and a zinc compound are mentioned specifically ,. Examples of the tin compound include organic tin compounds such as tin halides such as tin chloride and tin bromide, dibutyl tin diacetate and dibutyl tin dilaurate, and the like, and zinc compounds include zinc chloride and zinc bromide. And zinc salts of organic acids such as zinc halide, zinc octylate and zinc laurate. As a curing reaction catalyst, a tin compound and a zinc compound may be used individually by 1 type, or may be used in combination of 2 or more, and may be used together with another hardening reaction catalyst.

In this invention, content ratio of (E) component is 0.01-1.5 mass% with respect to the total mass of resin solid content of (A) component, (B) component, and (C) component contained, Preferably, 0.02 to 1.0 mass%, particularly preferably 0.05 to 0.8 mass%. If the ratio of the component (E) is less than 0.01% by mass, the promoting effect on the curing reaction is not sufficiently exhibited, and when the ratio of the component (E) exceeds 1.5% by mass, the re-coating adhesion decreases due to excessive curing of the paint film. Not desirable

In addition, content ratio of (E) component is content ratio of the active ingredient of (E) component, and an active ingredient here means the component which does not contain a solvent etc., when diluting with a solvent.

As the primer according to the present invention, a colored pigment, a true pigment, an organic solvent, and various additives can be used as necessary. Examples of the color pigments include azo rake pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, quinonaphthalone pigments, dioxazine pigments, and quinacridone pigments. Inorganic pigments such as organic pigments, yellow chromium, yellow iron oxide, red iron oxide and titanium dioxide. Kaolin, talc, etc. are mentioned as an intrinsic pigment.

Moreover, as an organic solvent, if it can melt | dissolve each component, it will not specifically limit, It is preferable that it does not react with an isocyanate compound. For example, aliphatic hydrocarbons, such as n-hexane, n-heptane, n-octane, aromatic hydrocarbons, such as benzene, toluene, and xylene, halogenated hydrocarbons, such as chloroform and carbon tetrachloride, methanol, ethanol, n-propyl alcohol, Alcohols such as isopropyl alcohol, n-butyl alcohol, ethers such as dibutyl ether, tetrahydrofuran, 1,4-dioxane, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, acetic acid Ester, such as n-propyl and n-butyl acetate, etc. can be contained. These solvents may be used alone or in combination of two or more. The blending method of each component, the bright pigment, the coloring pigment, the organic solvent, and various additives, and the adding method of the resin can be carried out by various methods without particular limitation, and the mixing order and the addition order can also be performed in various ways. have.

As a suitable coating method using the primer according to the present invention, the primer is warmed as necessary and adjusted to a desired viscosity by adding an organic solvent, for example, air spray, air response spray, electrostatic air spray, flow coating (flow) Although coating may be carried out using a conventional coating device such as a coating device by a -coating, dip-coating type, or a brush or the like, air spray coating is preferred. 2-15 micrometers is preferable and, as for the dry paint film thickness of a primer paint film, 4-10 micrometers is especially preferable.

After coating the primer according to the invention, it is preferred to coat the top-coat paint with wet on wet without baking the primer. As top-coat paint, one-coat type paint, two-coat type paint, or three-coat type paint can be used, but the paint forming the top paint film layer is a two-liquid type urethane resin paint. It is preferable. The urethane resin-based top-coat paint is not particularly limited, but a paint film must be formed by reaction of a polyol and an isocyanate compound.

As the one-coat type top-coat paint, solid paint or metal tone paint can be used. The dry paint film thickness of the top-coat paint is preferably 15 to 40 µm, more preferably 20 to 35 µm. As a two-coat type paint, coloring basecoat paint, such as a metal basecoat paint, or a combination with pearltone basecoat paint and clear paint is common, and the dry paint film thickness of a basecoat paint is 10-20 micrometers. Preferably, 20-40 micrometers is preferable and, as for the dry paint film thickness of clear paint, 25-35 micrometers is more preferable. As a 3-coat type paint, the combination of a coloring basecoat paint, a pearl tone basecoat paint, and a clear paint is common, The dry paint film thickness of a coloring basecoat paint is 5-15 micrometers, and the pearltone basecoat paint is preferable. 5-15 micrometers is preferable, as for the dry paint film thickness of clear paint, 20-40 micrometers is preferable and 25-35 micrometers is more preferable. When these paints are overlaid, it is preferable that they are all wet-wet painted in an uncured state.

As baking and drying conditions of a urethane resin type top-coat paint, 5 minutes-3 days are preferable at 20-150 degreeC, More preferably, it is 10-30 minutes at 80-140 degreeC. As an example of the molded article which coats the primer which concerns on this invention, the molded article which consists of polyolefin materials, such as polyethylene and a polypropylene, and a plastic material containing polyolefin etc. is mentioned. Furthermore, it can apply to the molded article which consists of plastic materials, such as ABS resin, PC resin, and nylon.

In the present invention, the re-coating (re-painting) is, for example, to a molded article coated with the top-coat paint and cured to form a top-coat paint film, the primer and the top-coat paint according to the present invention in sequence Methods of coating, baking and curing, and sequentially coating the primer and top-coat paint paints according to the invention on plastic moldings, after baking and curing, recoating if dust is deposited or the paint film is flawed It includes how to do it. In this case, after removing the dust, the primer and the top-coat paint should be sequentially coated and baked in the same manner as the primary coating, when the primer is coated again without sanding the entire top-coat paint film. . In addition, re-coating (re-painting) obtains a paint film having excellent adhesion by sequentially coating and baking the primer and the top-coat paint, even if the top-coat paint film forming the base is partially peeled off. Can be.

Examples of coating products obtainable by the coating method according to the present invention include structural materials, metal products, plastic products, rubber products and the like. More specifically, automobiles, parts for automobiles (for example, parts of automobile bodies, bumpers, spoilers, mirrors, wheels, interior materials, etc., which can be made of various materials), metal plates such as steel plates, two-wheeled vehicles, Motorcycle parts, road materials (e.g. guardrails, traffic signs, soundproof walls, etc.), tunnel materials (e.g. sidewall plates, etc.), ships, railroad cars, aircraft, musical instruments, home appliances, building materials , Containers, office supplies, sporting goods, toys and the like.

In the following, the present invention will also be described in detail by production examples, examples and comparative examples. However, the present invention is not limited to these embodiments. Hereinafter, unless specifically mentioned, "part" and "%" mean a "mass part" and the "mass%", respectively. In addition, in Table 1-Table 6, the unit of the numerical value which shows the compounding quantity of each component is a mass part.

In addition, in the Example and the comparative example, evaluation of each item was performed by the following method.

<Evaluation method of paint and paint film>

( Storage stability of primer )

The primers were stored at 40 ° C. for 10 days, and the condition was evaluated according to the following criteria.

0: no abnormality

Δ: slight separation observed

×: significant separation was observed

( Coating workability of primer )

Commercially available black polypropylene plates (70 mm long, 150 mm wide, 3 mm thick) were wiped with isopropyl alcohol to remove contaminants or dust deposited on the samples to be coated. Thereafter, the viscosity of the primers shown in Tables 4 and 5 was adjusted with xylene to 11 seconds in Ford cup # 4 (20 ° C), coated with air spray, and then, according to the following criteria. Coating workability was evaluated.

0: Possible to coat without abnormality

×: coating cannot be made due to agglomeration of the paint, or it becomes a cobweb state during coating, and thus normal coating cannot be performed.

( Adhesion of Primary Top-Coat Paint )

On a commercially available black polypropylene plate as described above, on a primer paint film coated so that the dry paint film thickness is 6 to 8 µm, a dilution solvent (butyl acetate / xylene = 70/30 (mass ratio) ), The top-coat paint with the viscosity adjusted so that the paint viscosity becomes 12 seconds with Pod Cup # 4 (25 ° C), and left at room temperature for 5 minutes, and then at 90 ° C for 20 minutes. Keep and dry. The dry paint film thickness of the top-coat paint is 25 μm for 1-coat type, 15 μm for 2-coat type base paint, 10 μm for 3-coat type colored basecoat paint, 3-coat type The wet base was wetted to 8 μm for the pearl basecoat paint and to 30 μm for the clear paint, and to all coatings including the 2-coat type and the 3-coat type. The resulting coated plate was allowed to stand at room temperature for 60 minutes, and 11 cuts were made longitudinally and horizontally with a cutter knife to give 100 squares at 2 mm intervals on the paint film, and cellophane tape It was peeled by and the state was evaluated according to the following criteria.

0: The paint film is not peeled off (represented by the remaining square 100/100)

(Triangle | delta): A state with peeling in a part of paint film (notation of remaining square 90-99 / 100)

X: The state which has peeling to the paint film (notation with residual square 0-89 / 100)

If peeling is observed on the paint film, check whether the peeling site is between the base and the primer paint film or between the primer paint and the top-coat paint film.

( Adhesion of Primary Top-Coat Paint and Re-Coated Top-Coat Paint )

As described above, on a commercially available black polypropylene plate, on a primer paint film coated to form a film of 6 to 8 μm, through a wet on wet, a diluting solvent (butyl acetate / xylene = 70/30 (mass ratio ), The air-coated top-coat paint whose viscosity was adjusted to 12 seconds with Pod Cup # 4 (25 ° C.) was air spray coated, left at room temperature for 5 minutes, and then at 40 ° C. The minute was kept dry. The dry paint film thickness of the top-coat paint paint is 25 μm for 1-coat type, 15 μm for 2-coat type base paint, 10 μm for 3-coat type colored basecoat paint, The 3-coat type pearl basecoat paint was 8 mu m, the clear paint was 30 mu m, and the 2-coat type was also performed by wet on wet, including the 3-coat type. The coated plate was left at room temperature for 24 hours, air spray-coated primer, top-coat paint paint with wet-on-wet in the same manner as the primary, left at room temperature for 5 minutes, and then dried at 80 ° C. for 20 minutes. I was.

In order to test the obtained coating plate, it left for 60 minutes at room temperature, made 11 short-circuits longitudinally by a cutter knife, and filled with cellophane tape so that the paint film provided 100 squares at 2 mm intervals, and the said state, Was evaluated according to the following criteria.

0: The paint film is not peeled off (represented by the remaining square 100/100)

(Triangle | delta): A state with peeling in a part of paint film (notation of remaining square 90-99 / 100)

X: The state which has peeling to the paint film (notation with residual square 0-89 / 100)

Suzy Production Example  One( Dior  Preparation of Resin Solution)

1, 6 hexanediol (561 parts) and adipic acid (347.1 parts) were put into a 2 L glass flask provided with a thermometer and a stirrer, and gradually heated up to 140 ° C, and then heated up to 190 ° C over 3 hours. . The mixture was kept at 190 ° C. for 2 hours and the esterification reaction proceeded. The mixture was heated up to 210 ° C. over 2 hours, and esterification was performed until the resin acid value became 1 or less. The obtained resin was cooled and xylene (91.9 parts) was added to obtain a diol resin solution D-1 having a weight average molecular weight of 330 and a resin solid content (active ingredient) of 90 mass%.

Suzy Production Example  2 to 4 ( Dior  Preparation of Resin Solution)

Resin synthesis was carried out with the raw materials shown in Table 1 in the same manner as in Production Example 1 to obtain diol resin solutions D-2 to D-4 shown in Table 1. In Table 1, the raw material Cardura E-10 &quot; is a mono-glycidyl ester of Versatic Acid (manufactured by Japan Epoxy Resin Co.).

Suzy Production Example  5 (polyester Polyol  Preparation of Resin Solution)

In a 2 L glass flask equipped with a thermometer and a stirrer, butylethylpropanediol (187.3 parts), trimethylolpropane (18.8 parts), 1,6 hexanediol (94 parts), phthalic anhydride (31.3 parts), adipic acid ( 295.2 parts) was added, gradually raised to 140 ° C, and then heated to 190 ° C over 3 hours. The mixture was kept at 190 ° C. for 2 hours and the esterification reaction proceeded. The mixture was heated up to 210 ° C over 2 hours, and esterification was performed until the resin acid value became 10 or less. The obtained resin was cooled and xylene (373.4 parts) was added to obtain a polyester polyol resin solution C-1 having a weight average molecular weight of 14,000, a hydroxyl value of 45, an acid value of 8, and a resin solid content of 60 mass%.

Suzy Production Example  6 (polyester Polyol  Preparation of Resin Solution)

In the same manner as in Production Example 5, resin synthesis was carried out by the raw materials shown in Table 2, to obtain a polyester polyol resin solution C-2 shown in Table 2.

Suzy Production Example  7 (acrylic Polyol  Preparation of Resin Solution)

300 parts of xylene was put into the 2 L glass flask provided with the thermometer, the stirrer, the reflux condenser, and the monomer dropping device, and the temperature was gradually raised to reflux. While maintaining the reflux state, 180 parts of styrene, 30 parts of methyl methacrylate, 197 parts of stearyl methacrylate, and Praxel FM-2 (trade name, manufactured by Daiseru Kagaku Kogyo Co., Ltd.) 191.4 parts of methacrylic acid hydroxyethyl monomer to which 2 mol of ε-caprolactones are added, 1.8 parts of acrylic acid and Perbutyl Z (trade name, manufactured by Nippon Yushi Co.); t-butyl Peroxybenzoate) 17 parts of mixed solution was dripped from the dripping apparatus over 3 hours. After completion | finish of dripping, after maintaining the reflux state over 3 hours, 1 part of polymerization initiators perbutyl Z and 10 parts of xylene were mixed, and it was dripped from the dripping apparatus. Furthermore, after continuing reaction at the reflux temperature for 2 hours, 71.8 parts of xylene were added and it cooled to room temperature, and obtained the acrylic polyol resin solution C-3 whose resin solid content is 61 mass%.

Suzy Production Example  8 to 12 (acrylic Polyol  Preparation of Resin Solution)

In the same manner as in Production Example 7, resins were synthesized by the raw materials shown in Table 3, and the acrylic polyol resin solutions C-4 to C8 shown in Table 3 were obtained.

primer Production Example  One

Chlorinated polypropylene resin solution (trade name "Harden CY9122" manufactured by Toyo Kasei Kogyo Co., Ltd.), maleic anhydride modified chlorinated polypropylene resin, chlorine content 22 mass%, weight average molecular weight 50,000 to 60,000, 20% resin solid content) 487.5 parts, Taipei CR-90 (titanium oxide, manufactured by Ishihara Sangyo Co.) 99 parts, pigment black FW200 beads (carbon black, 0.1 part of Degussa Co., Ltd. and 0.9 part of TSY-1 (a yellow pigment, manufactured by Toda Pigment Co.) are added and dispersed until the particles become 15 µm or less. . When the desired particle size dispersion is reached, the dispersion is stopped and the blocked polyisocyanate (trade name "Desmodur BL3175", manufactured by Sumitomo Bayer Co., Ltd., HDI isocyanate blocked by MEK oxime Urate, NCO content 11.2%, residuals 75% on heating) 40 parts, 36.9 parts of acrylic polyol C-3 prepared by Resin Preparation Example 7, 5 parts of diol D-1 prepared by Resin Preparation Example 1, dibutyl 0.9 part of dibutyl tin dilaurate and 329.7 parts of xylene were added, and it stirred sufficiently, and obtained primer P-1 of the primer manufacture example 1 shown in Table 4.

primer Production Example  2 to 21

In the same manner as in Preparation Example 1, primers P-2 to P-21 shown in Tables 4 and 5 were obtained.

In the said table, the meaning of the brand name or abbreviation shown is as follows.

1) Taipei CR-90: Titanium oxide, manufactured by Ishihara Industrial Co., Ltd.

2) Acicular Titanium Oxide: Conductive Titanium Oxide, manufactured by Ishihara Industrial Co., Ltd.

3) Pigment Black FW200 Beads: Carbon Black, manufactured by Degusa Co., Ltd.

4) PR INTEX L: Conductive Carbon Black, manufactured by Degusa Co., Ltd.

5) TSY-1: Yellow Pigment, Toda Pigment Co., Ltd.

6) Hardene CY9122: Tong Yang Chemical Industry Co., Ltd., maleic anhydride modified chlorinated polypropylene resin, chlorine content 22 mass%, weight average molecular weight 50,000 to 60,000, heating residue 20 mass%

7) Superclone 892L: Japan Paper Chemical Co., Ltd., maleic anhydride modified chlorinated polypropylene resin, chlorine content 22 mass%, weight average molecular weight 60,000 to 70,000, heating residue 20 mass%

8) Death module BL3175: manufactured by Sumitomo Bayer Urethane Co., Ltd., HDI isocyanurate blocked with MEK oxime, NCO content 11.2 mass%, heating residue 75 mass%

9) Death Module BL3272MPA: Manufactured by Sumitomo Bayer Urethane Co., Ltd., HDI isocyanurate blocked with ε-caprolactam, NCO content 10.2 mass%, heating residue 72 mass%

10) Death Module BL4265SN: manufactured by Sumitomo Bayer Urethane Co., Ltd., IPDI isocyanurate blocked with MEK oxime, NCO content of 8.9 mass%, heating residue 65 mass%

Top-coat paint Production Example  1 (2-liquid type urethane resin paint for 1-coat)

45.5 parts of acrylic resin LB-9020 (BASF Coatings Japan Co.), heating residue 55 mass%, hydroxyl value 56 mgKOH / g), Taipei CR-90 (titanium oxide, Ishihara) 24 parts of Industrial Co., Ltd., pigment black FW200 beads (carbon black), 0.1 part of Degusa Co., Ltd. and 0.6 parts of TSY-1 (yellow pigment, manufactured by Toda Pigment Co., Ltd.) in a dispersion container, It was dispersed until it became 10 micrometers or less. Dispersion is stopped when the desired particle size dispersion is reached, 0.2 parts of surface modifier Modaflow (manufactured by Monsanto Co., acrylic copolymer, conductive residue of heating, oxidation%), 10 parts of xylene, and butyl acetate 13.2 parts were taken out, it was made to fully stir with a Disper, it was made uniform, and the main component which is the 2-liquid type top-coat paint T-1 for 1-coat use was prepared. As a curing agent, Sumidure N75 (manufactured by Sumitomo Bayer Urethane Co., Ltd., polyisocyanate resin, 75% of heating residue, 16.5 mass% of NCO content) was used, and 93.6 parts of the main component and a uniform amount of curing agent 6.4 were immediately before coating. Mix until used.

Top-coat paint Production Example  2 (basecoat paints for 2-coat applications)

Acrylic resin LB-9020 (made by BASF Coatings Japan Co., Ltd., 55 mass% of heating residue, 56 mgKOH / g of hydroxyl value) 45.5 parts, the rheology control agent LC-0988 (made by BASF Coatings Japan Co., Ltd.), Inorganic system, 10 parts by mass of heating residue 6 parts, aluminum flake pigment Alpaste TCR3040 (trade name, Dongyang Aluminum Co., Ltd., 80 parts by mass of heating residue, average particle diameter (D ₅₀ ) 17㎛, average Thickness 0.8 μm) 2.5 parts, Al Paste 6340NS (trade name, Tong Yang Aluminum Co., Ltd.), 71% of heating residue, average particle size (D ₅₀ ) 13 μm, 3 parts average thickness 0.29 μm, Death module BL3175 (brand name, Sumitomo Bayer Urethane Co., Ltd., HDI isocyanurate blocked with MEK oxime, NCO content 11.2% by mass, heating residue 75% by mass 3.3 parts, surface modifier modaflow (manufactured by Monsanto Co., Ltd., acrylic copolymer, heating residue 100 % By mass), 10 parts of xylene, and 29.5 parts of butyl acetate were mixed. And stirred for 10 minutes with a disper to homogenize to prepare a 1-liquid type metal basecoat paint T-2 for 2-coat applications.

Top-coat paint Production Example  3 to 4 (basecoat paints for 2-coat applications)

In the same manner as in Top-Coat Paint Preparation Example 2, 1-liquid type metal basecoat paints T-3 to T-4 for the two-coat application shown in Table 6 were prepared.

Top-coat paint Production Example  5 (basecoat paints for 2-coat applications)

In the same manner as in the top-coat paint preparation example 2, the raw materials shown in Table 6 except for the Sumidur N75 were mixed and uniformly stirred to prepare a main component which was a 2-liquid type metal basecoat T-5 for 2-coat use. It was. As a hardening | curing agent, Smithdur N75 was mixed in the ratio of 96.5 parts of main components and 3.5 parts of hardening agents immediately before coating, and it stirred and used until it became uniform.

Top-coat paint Production Example  6 (coloured basecoat paints for 3-coat applications)

In the same manner as in the top-coat paint preparation example 1, the pigments shown in Table 6 were dispersed, the remaining raw materials except for the Sumidur N75 were added, followed by uniform agitation to give a 2-liquid type colored basecoat for 3-coat use. The main component, coat T-6, was prepared. As a hardening | curing agent, Sumidur N-75 was mixed in the ratio of 96.5 parts of main components and the hardening | curing agent 3.5 just before coating, and it stirred and used until it became uniform.

Top-coat paint Production Example  7 (coloured basecoat paints for 3-coat applications)

In the same manner as in Top-Coat Paint Preparation Example 6, the pigments shown in Table 6 were dispersed, the remaining raw materials were added, and then uniformly stirred to give 1-liquid type colored basecoat coat T-7 for 3-coat applications. Prepared.

Top-coat paint Production Example  8 (pearl basecoat paint for 3-coat applications)

Except for replacing the aluminum pigment with the pearl pigment, the main component was prepared in the same manner as in the top-coat paint preparation 5, which was a two-liquid type pearl basecoat coat T-8 for 3-coat use. As a hardening | curing agent, Sumidur N-75 was mixed in the ratio of 96.5 parts of main components and the hardening | curing agent 3.5 just before coating, and it stirred and used until it became uniform.

Top-coat paint Production Example  9 (pearl basecoat paint for 3-coat applications)

A pearl basecoat coat T-9 was prepared in the same manner as in the top-coat paint preparation example 2, except that the aluminum pigment was also replaced by the pearl pigment.

Top-coat paint Production Example  10 ( clear  Paint)

80 parts of acrylic resin LB-9040 (manufactured by BASF Coatings Japan Co., Ltd., heating residue 55% by mass, hydroxyl value of 78 mgKOH / g) is mixed with 0.2 part of surface modifier modaflow and 4.8 parts of butyl acetate, and is mixed with a disper for 10 minutes. The mixture was stirred and uniformed to prepare a two-liquid type clear paint T-10 main component. As a hardening | curing agent, Sumidur N-75 was mixed in the ratio of 85 parts of main components and hardening | curing agent 15 just before coating, and it stirred and used until it became uniform.

In the said table, the meaning of a brand name or an abbreviation is as follows.

11) Iriodin 103WNT: manufactured by Merck Co., mica pigment

12) Alpaste TCR3040: Toyo Aluminum Co., Ltd., aluminum pigment, heating residue 80 mass%, average particle diameter (D ₅₀ ) 17㎛

13) Alpaste 6340NS: Tong Yang Aluminum Co., Ltd., aluminum pigment, 71% by mass of heating residue, average particle diameter (D ₅₀ ) 13㎛

14) Sumidure N-75: Manufactured by Sumitomo Bayer Urethane Co., Ltd., polyisocyanate resin, 75% heating residue, 16.5 mass% NCO content

15) Yuban 122: manufactured by Mitsui Kagaku Co., Ltd., butylated melamine resin, heating residue 60% by mass

16) Modaflow: Monsanto Co., Ltd., acrylic copolymer, heating residue conductivity oxidation%

( Example 1 )

P-1 is used as the primer, T-1 is used as the top-coat paint, and according to the paint and paint film evaluation method, storage stability of the primer, coating workability of the primer, after coating with the top-coat paint The adhesion test of the primary top-coat paint and the adhesion of the primary top-coat paint and the re-coated top-coat paint were carried out, and the evaluation results are shown in Table 7.

( Examples 2 to 12 )

The test was carried out in the same manner as in Example 1 except that the top-coat paint was replaced with the combination shown in Table 7, and the evaluation results are shown in Table 7.

( Comparative Examples 1 to 9 )

The test was carried out in the same manner as in Example 1 except that the top-coat paint was replaced with the combination shown in Table 8, and the evaluation results are shown in Table 8.

The primer according to the present invention, as shown in Examples 8 to 12 of Table 7, the adhesion of the re-coated paint film is somewhat reduced, but from a practical point of view is a problem level, the primer according to the present invention is excellent storage stability and A paint film having a coating workability, thereby having no problem in adhesion with the primary top-coat paint film and the re-coated paint film, is obtained.

However, as shown in Comparative Examples 1-4, when making (A), (B), and (C) component into components other than a claim, Comparative Example 1, Comparative Example 2, and Comparative Example 4 As in, the adhesion of the material and the primer is lowered, or as shown in Comparative Example 3, the adhesion of the primer and the top-coat paint is slightly lowered, and the re-coating adhesion is insufficient. In addition, when the characteristic value of the mixed polyol is outside the scope of the claims, the adhesion between the material and the primer is reduced, as shown in Comparative Example 5, or the coating workability of the primer as shown in Comparative Examples 6 and 7 And storage stability. Moreover, when (D) component and (E) component become other than the component which concerns on this invention, as shown in the comparative example 8 and the comparative example 9, re-coating adhesiveness becomes inadequate.

From the above results, the primer according to the present invention has a storage stability and coating workability of the primer, and according to the present invention, a coated article excellent in adhesion with the primary top-coat paint film and re-coating adhesion is obtained. .

Claims (7)

(A) a chlorinated polyolefin resin having a chlorine content of 5 to 50 mass% and a weight average molecular weight of 1,000 to 100,000, (B) a blocked polyisocyanate compound, (C) a hydroxyl value of 30 to 120 mgKOH / g, and a weight average molecular weight of 5,000 (A) component, (B) component and (C) containing a polyol resin having from 50,000 to 50,000, (D) a diol having a weight average molecular weight of 120 to 1,000, and (E) a curing catalyst, the content ratio of the components being contained (A) component is 50-90 mass%, (B) component is 45-5 mass%, (C) component is 45-5 mass%, and (D) component is 0.5 with respect to the total mass of resin solid content of the component. Primer, characterized in that from 0.01 to 1.5% by mass to 12% by mass, (E) component. A coating method of a plastic molded article, characterized by sequentially coating, baking and curing the primer and top-coat paint according to claim 1 on a plastic molded article to form a top-coat paint film. . After sequentially coating, baking and curing the primer and top-coat paint according to claim 1 on the plastic molded article, the primer and top-coat paint according to claim 1 are sequentially applied on the top-coat paint film. Coating, baking and curing, wherein the coating method of the plastic molded article. Coating, baking and curing sequentially the primer and the top-coat paint according to claim 1 on the top-coat paint film of the molded article on which the top-coat paint is coated, cured and the top-coat paint film is formed. The coating method of the molded article characterized by the above-mentioned. The molded article according to claim 2, wherein the top-coat paint is a one-coat type two-liquid type urethane resin paint. Coating method. 5. The method of claim 2, wherein the top-coat paint film comprises two layers of a base coat paint film and a clear paint film, wherein at least clear paint is 2 -Coating method of molded article which is liquid type urethane resin paint. The method of claim 2, wherein the top-coat paint film is a colored base-coat paint film, a pearl base-coat paint film and a clear. A method of coating a molded article comprising three layers of paint film, wherein at least the clear paint is a two-liquid type urethane resin paint.